Yes: I can see in your post that you have already read about that, but now your situation may well be different.

Either (or both) of two things has happened:
The battery has been over-discharged enough that it can no longer hold enough charge, OR
The battery has been discharged to the point that the internal battery management can no longer re-charge it.

Remove battery from Kindle, recharge it with an "Amazon Approved" re-charger.
That is the "official" company line.

For DIY situation - you can use any general purpose Li-Ion charger, OR
You can "fake it" -
Use a constant current, voltage limited, charging source;
Recharge at 30% of the listed (on the battery) one-hour rate for two hours.
Do not exceed a terminal voltage of 4.2 volts under charge;
Do not let the temperature of the battery raise enough to damage it.

That **might** (if not suffering from lack of charge holding capacity) get the battery back to a condition where you can get the Kindle into the "fastboot" re-charge mode.

I have used the option I and E (so i am able to transfer some files through the usb). Also i have downloaded the update 5.1.0.bin and tryed to use option U (I get the message:No updates found: No updates needed).

First thing that came on my mind is to use the update 5.1.0.bin. To use this, i think i need to modify the firmware version (the reason of the message "No updates found: No updates needed" ? ) so the kindle use this update (now the firmware is 5.1.0 already). The question is, this update will install my kernels back or u-boot bist?

Also, i could modify the custom u-boot again in order to load some data in memory, but i don't know exactly how should i do this, or what data should i load.

I can't reflash my kernels back with fastboot becouse u-boot bist is missing (kernels and partitions are gone).

I've took a look at how fastboot is implemented in U-Boot. Unfortunately, I can't try validness of my research, as I have no access to serial console, but it should be enough to include following defines into include/configs/imx50_yoshi.h:

I have used the option I and E (so i am able to transfer some files through the usb). Also i have downloaded the update 5.1.0.bin and tryed to use option U (I get the message:No updates found: No updates needed).

First thing that came on my mind is to use the update 5.1.0.bin. To use this, i think i need to modify the firmware version (the reason of the message "No updates found: No updates needed" ? ) so the kindle use this update (now the firmware is 5.1.0 already). The question is, this update will install my kernels back or u-boot bist?

Also, i could modify the custom u-boot again in order to load some data in memory, but i don't know exactly how should i do this, or what data should i load.

Also, is it possible to install/use ssh in this condition?

Thank you

I'm not entirely sure... (what was that bist beast about again?) - but if you managed to repartition it - shouldn't your device be back in a state where you can use USB downloader mode? Give it a try with mfgtool or imx_usb_loader and the fastboot.bin u-boot (found inside the mfgtool download). If you're lucky, this will get you into fastboot mode where you could flash the debrick kernels and ssh-enabled diags partition, and then you could reboot into diags. Or did I miss something?

I'm not entirely sure... (what was that bist beast about again?) - but if you managed to repartition it - shouldn't your device be back in a state where you can use USB downloader mode? Give it a try with mfgtool or imx_usb_loader and the fastboot.bin u-boot (found inside the mfgtool download). If you're lucky, this will get you into fastboot mode where you could flash the debrick kernels and ssh-enabled diags partition, and then you could reboot into diags. Or did I miss something?

"bist" is the second-stage U-Boot, which is loaded by ordinary, first-stage U-Boot. bist U-Boot is bigger than ordinary U-boot and bigger than OCRAM size, so it can't be loaded right after restart. Initially, ordiinary U-Boot (which is loaded into OCRAM) initializes DRAM, then it loads bist U-Boot into DRAM (<later EDIT> only after explicit request from ordinary U-Boot console accessible through serial connection or from setting value of idme variable bootmode to fastboot etc. </later EDIT>). bist U-Boot is more featureful (that's why it's bigger). For example, fastboot mode is included into bist U-Boot, but it's not in oridinary U-Boot.

BTW, I think you're right and loading of fastboot.bin (through USB downloader mode) should work as usually.

I'm not entirely sure... (what was that bist beast about again?) - but if you managed to repartition it - shouldn't your device be back in a state where you can use USB downloader mode? Give it a try with mfgtool or imx_usb_loader and the fastboot.bin u-boot (found inside the mfgtool download). If you're lucky, this will get you into fastboot mode where you could flash the debrick kernels and ssh-enabled diags partition, and then you could reboot into diags. Or did I miss something?

You mean i should run sb_loader -f fastboot.bin (from MfgConfig) while in Recovery mode? Can karnel img be loaded with sb_loader too?

I didn't tryed sd_loader until now, but as i read, i should be able to do this while in Recovery menu.

I will try also to modify the u-boot to load fastboot, as eureka suggested, as soon as i get home.

You mean i should run sb_loader -f fastboot.bin (from MfgConfig) while in Recovery mode? Can karnel img be loaded with sb_loader too?

I didn't tryed sd_loader until now, but as i read, i should be able to do this while in Recovery menu.

I will try also to modify the u-boot to load fastboot, as eureka suggested, as soon as i get home.

Thank you

I'm not familiar with the mfg* stuff (I try to avoid Windows as much as I can), so I don't know what the command-line tools you mentioned mean.

Essentially, mfgtool comes with a GUI to load and start stuff on a Kindle which is in USB downloader mode, and it includes 3 custom u-boot images (fastboot, diags, main). imx_usb_loader does the same, but through a command line. I obviously prefer the latter, because it "just works" on Linux, no need for Windows, no need for Windows driver hell.

But if I'm correct, and your device works in USB downloader mode, both should do the job of getting your device into fastboot mode, from where you can follow the "normal" debricking procedure. So use whichever OS/tool you prefer

I'm not familiar with the mfg* stuff (I try to avoid Windows as much as I can), so I don't know what the command-line tools you mentioned mean.

Essentially, mfgtool comes with a GUI to load and start stuff on a Kindle which is in USB downloader mode, and it includes 3 custom u-boot images (fastboot, diags, main). imx_usb_loader does the same, but through a command line. I obviously prefer the latter, because it "just works" on Linux, no need for Windows, no need for Windows driver hell.

But if I'm correct, and your device works in USB downloader mode, both should do the job of getting your device into fastboot mode, from where you can follow the "normal" debricking procedure. So use whichever OS/tool you prefer

I have already tryed with MfgTool to fastboot but it's stuck on waiting device.
The reason it's that fastboot is included in bist U-Boot, and cannot be started because it's missing (tryed in U-Boot command to run bist and nothing happened). As Eureka suggested to load fastboot in U-boot binary should work (at least in theory ). By running fastboot in MfgConfig, the fastboot still need to be loaded by U-boot bist.

I have already tryed with MfgTool to fastboot but it's stuck on waiting device.
The reason it's that fastboot is included in bist U-Boot, and cannot be started because it's missing (tryed in U-Boot command to run bist and nothing happened). As Eureka suggested to load fastboot in U-boot binary should work (at least in theory ). By running fastboot in MfgConfig, the fastboot still need to be loaded by U-boot bist.

Ah ok, that makes sense now. If you manage to compile a working "single-stage" u-boot which goes directly to fastboot, please also post it here - it may be useful for other folks.

The custom u-boot images I built, which are included in the MfgTool profiles, are the first-stage u-boot that fits in OCRAM, with the addition of a single line of code that temporarily sets the bootmode to one of (main, diags, fastboot).

When you use the fastboot version, it initializes SDRAM, and then loads the larger u-boot bist (Built-In Self-Test) from mmc into SDRAM. The kindle fastboot protocol resides in u-boot bist. With an erased mmc, it cannot load and cannot support fastboot mode.

It would be possible to create a (more complex) MfgTool profile that can also load u-boot bist over USB.

But with existing tools, the easiest method may be to flash mmc (including u-boot bist) over serial.

One problem is that the portion of /dev/mmcblk0 that contains u-boot and u-boot bist appears to be all zeros when you make a backup copy of the first 32MB. It may be necessary to export a backup of the mmc using the serial port...

Does anybody know how to get a backup image of u-boot bist from the mmc on a K4 or K5?